It is not unknown for ministers to be sued in the civil courts. During the last Conservative government, both John Patten and Michael Heseltine were sued – separately and successfully – for libel. The rule of thumb in such cases is that if the minister is found to have transgressed while performing ministerial duties (as was the case with Lord Heseltine), the government covers any damages, while if he was acting in a private or party political capacity (as was Lord Patten) he has to foot the bill himself. This may come as a relief to Jack Straw, the former foreign secretary, who is being sued by Abdel Hakim Belhadj, former leader of the Libyan Islamic Fighting Group (LIFG). Mr Belhadj alleges that Mr Straw personally authorised his rendition in 2004 when he was seized by CIA agents and handed over to the Libyan dictator, Muammar Gaddafi. The LIFG had links to al-Qaeda and Mr Belhadj claims he was tortured by the Libyan regime. He is already suing the British government and its security services.

Rendition is not a crime. The British government’s position on this was set out in 2008 by the then foreign secretary, David Miliband. He said that the agreement this country has with the United States meant permission for rendition via UK territory or airspace would be given only if it accorded “with UK law and our international obligations; and how we understand our obligations under the UN Convention Against Torture”. If rendition is not a criminal offence, complicity in torture is, and in his complaints against Mr Straw and the British government, Mr Belhadj appears to be eliding the two. Yet Mr Straw last year explicitly denied any involvement in torture: “We were opposed to any use of torture or similar methods. Not only did we not agree with it, we were not complicit in it and nor did we turn a blind eye to it.”

It is self-evident that criminal allegations against a minister should be investigated by the police. But civil actions, where the burden of proof is less rigorous, are more problematical. The difficulty facing both Mr Straw and the Government is the reluctance of the intelligence services to contest such accusations as Mr Belhadj’s in the civil courts because it would expose their own officials to unwanted public scrutiny. This is what led to the payment of many millions of pounds in compensation to 16 Guantánamo detainees two years ago. Perhaps it is the prospect of such easy pickings that lies behind this case. In these circumstances, and in the unlikely event of this case ever reaching the courts, fairness demands that Mr Straw be indemnified against financial outlay. Otherwise a dangerous precedent will have been set in a complex and contentious area.